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An explosion rocked the AGP plant at 3:19 a.m. Thursday damaging an extensive area when an external hydrogen tank blew to pieces.

No injuries were reported after an South Side explosion rumbled through St. Joseph early this morning.

City and county law enforcement were called to Ag Processing on the Stockyards Expressway around 3:19 this morning. According to St. Joseph Police Captain Matt Rock, an external hydrogen holding tank exploded. Twenty-five to 30 employees were at the plant at the time of the explosion with 10-15 in the area of the explosion but no injuries were reported.

City public relations officer Mary Robertson confirmed the incident details at a press conference later at city hall.

St. Joseph Fire Department Chief Mike Dalsing said he believed no one was injured because the explosion occurred outside on the south side of the facility and, because hydrogen is a light gas, the explosion rose in the air instead of spreading out. Also, he said that AGP has been fully cooperative with advanced emergency planning and when firefighters arrive on the scene, plant officials were able to account for all employees and direct emergency responders to the exact location of the explosion.

Mr. Dalsing also said the tank was one of six hydrogen storage tanks. The explosion in the lone tank caused fires throughout the tank holding area but employees and firefighters were able to use nitrogen to purge all six tanks and avoid further explosions.

AGP had just taken delivery of a supply of hydrogen prior to the incident but Mr. Dalsing declined to connect the delivery with the explosion. He did say that the explosion's debris field extended 70-80 feet to the south of the holding tank. To the north, debris was found as far as 180 feet away. Another building at AGP suffered some structural damage, including bent i-beams.

Mr. Dalsing said most of St. Joseph felt the explosion. He lauded the efforts of the several emergency responders, including AGP workers and KCP&L. "All in all, it went really well," he said.

Two investigators remain on the scene to try to determine the exact cause.

Workers from neighboring buildings were allowed to return after 5:30 this morning. One witness said he heard a hiss, saw the explosion, and then heard the explosion.

There is no estimate on the extent of damages.